BCS-BEC crossover on the two-dimensional honeycomb lattice.

  title={BCS-BEC crossover on the two-dimensional honeycomb lattice.},
  author={Erhai Zhao and Arun Paramekanti},
  journal={Physical review letters},
  volume={97 23},
The attractive Hubbard model on the honeycomb lattice exhibits, at half filling, a quantum critical point between a semimetal with massless Dirac fermions and an s-wave superconductor (SC). We study the BCS-BEC crossover in this model away from half filling at zero temperature and show that the appropriately defined crossover line (in the interaction-density plane) passes through the quantum critical point at half filling. For a range of densities around half filling, the "underlying Fermi… Expand
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